High pressure ammonia development device



Sept.'12, 1967 E. H. STO RM 7 HIGH PRESSURE AMMONIA DEVELOPMENT DEVICE Original Filed Feb. 5, 1965 INVENTOR 5 ELWOOD HLSTORMI ATTORNEY United States Patent 3,340,786 HIGH PRESSURE AMMONIA DEVELOPMENT DEVICE Elwood H. Storm, 35 Pasatiempo Drive, Santa Cruz, Calif. 95060 Original application Feb. 3, 1965, Ser. No. 430,094. Divided and this application Apr. 5, 1965, Ser. No.

2 Claims. c1. 9s-s9 ABSTRACT OF THE DISCLOSURE This is a division of application Ser. No. 430,094, filed Feb. 3, 1965.

This invention relates in general to a development method and apparatus wherein developer fluids or gasses are presented at pressures greater than ambient to a member to be developed and more particularly to a developnient method and apparatus for developing a film surface in a sealed development device by purging a portion of the air trapped therein by means of the developer fluid.

In United States patent application Ser. No. 369,861, entitled, Diazo Development Process, assigned to the assignee of the present application, there is provided a development process which enables the development of ammonia sensitive films such as diazo in a fraction of a second. This process, simply stated, involves applying the developing ammonia to the surface to be developed at a relatively high pressure, such as for instance, 90 p.s.i.g. Obviously, to utilize this process, tight developer platen to film sealing is necessary.

Experience with the high pressure ammonia development process has demonstrated non-uniform image development when the necessary tight developer platen to film sealing is achieved. This non-uniformity often includes film areas that appear completely undeveloped even 7 to the naked eye while adjacent film areas appear to be fully developed. This non-uniformity of development is due to the. entrapment of air between the film surface and the developer platen at the time the film is sealed to the developer platen.

Several solutions to this problem of entrapped air are available. Mixing of the air and ammonia is one of the more obvious. However,'while relatively good mixing in a short period of time can be achieved in round develop ment chambers, it is diflicult to achieve uniform mixing in a rectangular or square shaped chamber in a .short period of time. A rectangular development chamber is most often required since one of the largest applications for rapid ammonia development is in the development of aperture cards or similar micro images where the information format is rectangular.

While the development time may be extended to assure development of all film areas, a significant increase in the development time (2X or more) is required to achieve even limited improvement. The attempt to avoid underdeveloped areas by increasing the development period both compromises the high speed advantage of the process and overdevelops most of the film image area. Overdevelopment may not change the photometric properties of a developed image, but, by increasing the total quantity of ammonia absorbed by the film, it causes an increase in both ammonia consumption and the quantities of ammonia subsequently released by the film. This excessive absorption of ammonia associated with overdevelopment may, particularly with acetate base film materials, also cause deleterious mechanical effects such as film curl.

Another solution to the problem is evacuation of the entrapped air. If a developer platen is evacuated after sealing, and before the introduction of ammonia, by special valving and vacuum source means, non-uniformity due to air entrapment can be avoided. The evacuation approach obviously suffers from increased machine complexity.

Uniform development may also be achieved by permitting some leakage at the film to developer seal so that the entrapped air is forced out of the platen cavity by the introduction of ammonia. Developer platens have been built using this controlled leak seal approach. Uniform development has been achieved with the both metal to film seals and elastomer to film seals where the entire seal periphery permitted some leakage. The approach suffers from the fact that the air is followed by ammonia gas which not only is highly corrosive, but additionally is poisonous in relatively low concentrations.

It is therefore an object of the present invention to provide a novel method of utilizing the high pressure ammonia development process with minimum ammonia consumption.

Another object of the present invention is to provide a new method of uniform image development of a film area sealed to a high pressure ammonia developer platen where entrapped air is present at the instant of ammonia introduction, and where a portion of entrapped air is removedfrom the surface of the image area by other than evacuation or controlled leakage.

Another object of the present invention is to provide a new development device suitable for use in a development process wherein a portion of the entrapped air is forced by means of incoming. ammonia into an entrapment cavity.

Another object of the present invention is to provide a new development device in which incoming ammonia is mixed with a portion of the entrapped air and wherein air escape ports are provided for removal of the remaining portion of unmixed air to an air entrapment cavity by the incoming ammonia.

Other and further objects and advantages of the invcntion will be apparent from the following more particular description of the preferred embodiment of the invention as illustrated in the accompanying drawings in which:

FIG. 1 is a perspective view of the development device in accordance With the present invention wherein the air entrapment reservoir is located on the outer periphery of the development cavity and air escape ports are located adjacent the corners of the development chamber; and,

FIG. 2 is a cutaway side view taken along lines 22 of FIG. 1. Briefly, in the preferred embodiment, for accomplishing the subject method of development, there is provided a novel rectangular development chamber having escape ports in each corner. With this arrangement, high pressure anhydrous ammonia entering through a centrally located inlet port spreads through the chamber mixing with entrapped air and in so doing forces any air trapped in the corners of the chamber out of the escape ports and into and air entrapment cavity which results in a uniform distribution and concentration of anhydrous ammonia over the entire film surface. The ports for entrance of ammonia and escape of the unmixed portion of the entrapped air are geometrically placed such that the entire film surface is cleared of unmixed entrapped air.

The device of FIGS. 1 and 2 resulted from attempts to develop rectangular film areas such as the film insert in a conventional aperture card. Prior experimentation with various types of diffusers for diffusing or dispersing the entering ammonia had led to the development of a conical type diffuser which caused the entering ammonia to be mixed with the entrapped air in a circular development chamber. In developing a rectangular type development device the natural step with therefore to incorporate a conical diffuser into it to assure complete mixing of the incoming ammonia and entrapped air. With ammonia injected through a conical diffuser into a rectangular development chamber totally unsatisfactory development occurred. The portions of the film area adjacent the corners of the development chamber were completely undeveloped. Increasing the development time not only frustrated the prime objective of the high pressure ammonia dervelopment method; i.e., high speed, but additionally did not materially add to the development of the corner portions. A period of extensive unsuccessful experimentation followed during which numerous diffusers were tested in an attempt to achieve complete mixing of the ammonia and entrapped air.

The unsuccessful device was similar to that shown in FIGS. 1 and 2 with the exception that the outboard seal 3 was not present and the cutaway portions 10 of the internal seal 2 had not been made such that the metal seal was continuous and sealed the development cavity. It was adjacent the cutaway portions 10 that the unmixed entrapped air accumulated. The subject novel method and device of FIGS. 1 and 2 was then conceived.

For a more detailed description of the subject invention, refer to FIGS. 1 and 2 wherein is shown a developer platen or device 1 having on its film receiving face a raised four pieced inner metal seal 2 and an outboard elastomer seal 3. In one device actually constructed to metal seal surfaces 4 were raised approximately .008" above the surface of the plate 5 to provide an .008" high cavity. As shown in FIG. 2, film 6 in an aperture card 7 is adapted to be held against top surface 4 of the seal 3 by means of a fiat backup or closure platen 8 with its emulsion surface 9 facing the developer platen 1. The emulsion surface is urged against the inner metal seal 2 and the elastomer seal 3 by the action of flat closure platen 8. The corners of the metal seal 2 are cut away as at 10 to permit flow of the unmixed entrapped air into the surrounding cavity or reservoir space 11 created between the metal seal 2 and the elastomer seal 3.

After sealing of the film 6 to the platen, ammonia is introduced through a conduit 14 by opening valve 12. The ammonia is diffused into the development chamber 15 through the ammonia entrance port 13. As stated previously to get good mixing a conical diffuser (not shown) can be inserted in the entrance port 13. This is not absolutely necessary since mixing will take place with direct injection of the ammonia. The most effective way is, however, with a diffuser.

The introducti n of high pressure ammonia into the development chamber in the range of 50 to p.s.i.g. forces any unmixed entrapped air through the air escape ports 10 in the metal seal 2 and into the reservoir or air entrapment cavity 11. The elastomer seal 3 provides a gas tight seal between the platen 1 and the film 6 to prevent the escape of any air or gas to the exterior machine environment. This combination of seals thus provides for uniform development of the image area contained within the dimensions of the metal seal 2 without the requirement for evacuation means.

The reservoir 11 should be sized relative to the pressurized volume of the development chamber so that at any given operating pressure some ammonia fiow will occur through all air escape ports to assure the removal of all unmixed entrapped air before the pressure in the air entrapment cavity and the developer chamber 15 equalize.

While this invention has been described in terms of its use as an ammonia developer for diazo films in and out of aperture cards, it has also been successfully applied to the development of diazo treated paper and the use of the word film in the following claims is intended to encompass any photo-sensitive material.

The invention may also be applied to other than diazo film materials and may be used with fluids or gasses other than ammonia.

Briefly, for accomplishing the subject method of film development, there is provided a novel developer device wherein air escape ports 10 are provided adjacent the corners of the rectangular development chamber 15 at points distant from an ammonia injection port 13 such that the entering ammonia while mixing with the major portion of the trapped air, forces the remaining unmixed air ahead of it into the air escape ports and thence into the air entrapment cavity 11 which results in a uniform concentration of ammonia being presented to the film surface 9. The port for entrance of ammonia and escape of the unmixed entrapped air is geometrically placed such that the entire film surface is cleared of unmixed entrapped air.

While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it Will be understood by those skilled in the air that various changes in the form and details may be made therein without departing from the spirit and scope of the invention.

What is claimed is:

1. In a developer device for applying a gas to a discrete film area, the combination comprising:

a film developing platen with a film seal,

said seal being shaped to enclose said film area,

a closure platen operative to hold said film against said seal,

a development chamber formed by said developing platen, said discrete film area and said seal,

and air entrapment cavity,

first porting means for introducing gas into said development chamber, and

second porting means passing through said seal interconnecting said development chamber and said air entrapment cavity,

said second porting means positioned relative to said first porting means such that when said seal is in contact with said film area and pressurized gas is introduced into said development chamber, a portion of the entrapped air is forced through said second porting means into said air entrapment cavity.

2. In a developer device for appling a gas to a discrete film area, the combination comprising:

a film developing platen with an outboard seal,

an inner rectangular seal having an air escape port at each of the corners thereof,

said inner seal being shaped to enclose said film area and to form an air entrapment cavity between it and said outboard seal,

5 6 a closure platen operative to hold said film area against References Cited said inner and out-board seals, UNITED STATES PATENTS a development chamber formed by said developing platen, said discrete film area and said inner seal, and 3,229,608 1/1966 Stau'b et 95-89 porting means for introducing gas into said develop- 5 FOREIGN PATENTS .ment 341,972 1/1931 Great Britain. sa1d porting means positloned relative to said an escape 711 314 1/1954 Great Britain ports such that when said seals are in contact with said film area and pressurized gas is introduced into said development chamber, a portion of the entrap- 1O NORTON ANSHER Primary Exammer' ped air is forced into said air entrapment cavity along FRED BRAUN, Assistant Examinen with little or none of said gas.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,340,786 September 1 2 Elwood H. Storm It is nereoy certified that error appears in the above numbered pew ent requiring correction and that the said Letters Patent should read as corrected below in the heading to the printed specification, lines 4 rm-ri' S tor "Elwood H. Storm 35 Pasatiempo Drive Santa Cruz C3 l1 1 95060" read Elwood H. Storm, Santa Cruz, Calif. assignor 1 International Business Machines Corporation, Armonk N. Y a corporation of New York Signed and sealed this 10th day of September 1968,

(SEAL) Attest:

Edward M. Fletcher, Jr. EDW'ARD B R ENNER Attesting Officer Commissioner of Patents 

1. IN A DEVELOPER DEVICE FOR APPLYING A GAS TO A DISCRETE FILM AREA, THE COMBINATION COMPRISING: A FILM DEVELOPING PLATEN WITH A FILM SEAL, SAID SEAL BEING SHAPED TO ENCLOSE SAID FILM AREA, A CLOSURE PLATEN OPERATIVE TO HOLD SAID FILM AGAINST SAID SEAL, A DEVELOPMENT CHAMBER FORMED BY SAID DEVELOPING PLATEN, SAID DISCRETE FILM AREA AND SAID SEAL, AND AIR ENTRAPMENT CAVITY, FIRST PORTING MEANS FOR INTRODUCING GAS INTO SAID DEVELOPMENT CHAMBER, AND SECOND PORTING MEANS PASSING THROUGH SAID SEAL INTERCONNECTING SAID DEVELOPMENT CHAMBER AND SAID AIR ENTRAPMENT CAVITY, SAID SECOND PORTING MEANS POSITIONED RELATIVE TO SAID FIRST PORTING MEANS SUCH THAT WHEN SAID SEAL IS IN CONTACT WITH SAID FILM AREA AND PRESSURIZED GAS IS INTRODUCED INTO SAID DEVELOPMENT CHAMBER, A PORTION OF THE ENTRAPPED AIR IS FORCED THROUGH SAID SECOND PORTING MEANS INTO SAID AIR ENTRAPMENT CAVITY. 